After months of legal filings and lawyers wrangling, a panel of three federal judges in San Antonio listened to opening arguments Tuesday morning in a key trial that encompasses several challenges to the state’s redistricting maps.

Minority groups charged in their opening statements that Republicans in the Texas legislature actively worked to dilute the voting power of minority voters. Their method: packing them into existing minority districts and failing to create new minority opportunity districts to reflect the state’s booming Hispanic and African American populations.

The maps passed by the Texas Legislature amounted to a “racial gerrymander” that represented “intentional discrimination,” Jose Garza, attorney for the Mexican American Legislative Caucus, told the judges.

Garza said the evidence the minority groups had been able to collect through the court process so far almost amounted to a smoking gun that discrimination against minorities was a driving motivation behind the design of the map.

Key Republicans involved in the redistricting process have long denied the charges, pointing to logistical challenges of drawing additional minority districts when the population boom was spread out across all areas of the state.

They’ve argued that the minority groups and the Democratic Party have taken the maps to court to get a map that they couldn’t win at the ballot box.

State attorney David Schenck said “fixing” an election outcome “with racial gerrymandering… is an unconstitutional stretch” of the Voting Rights Act.

Rep. Trey Martinez Fischer, the Mexican American Legislative Caucus’ first witness, testified that the state leadership had taken an absurd position by making only one of the state’s four new congressional districts a minority opportunity seat, even though minorities had accounted for 90 percent of the state’s population growth, with Hispanics making up the largest share of the increase.

The four seats gained by Texas during the reapportionment process was the largest increase in representation Texas has seen since Reconstruction, Fischer said, calling the four new seats an unprecedented opportunity for Hispanic voters in Texas to increase their representation in the statehouse and Congress.

Throughout the morning, minority groups argued that not only did the maps prevent minority voters from gaining a sufficient number of new seats based on what Texas gained from population growth, but the maps also reduced the amount of minority representation in the statehouse and in the Texas congressional delegation.

Fischer pointed out that the state House redistricting map passed by the Legislature combined the districts of Reps. Scott Hochberg and Hubert Vo, both of whom represent heavily Democratic minority opportunity districts in the Houston area.

In her opening arguments for the Mexican American Legal Defense and Education Fund, Nina Perales said minority voting blocs in the Rio Grande Valley and along the South Texas coast had been fractured by the redistricting effort, specifically pointing to where a redrawn congressional district had split Eagle Pass.

She called the redistricting effort a “sham.”

Attorney Gerry Hebert, who represents a group of plaintiffs from Fort Worth and Houston, said the dilution of the Hispanic vote in two South Texas congressional districts made sense from a political standpoint but it had violated the Voting Rights Act.

“[The] minority community was sliced and diced to prevent them from electing the candidate of their choice,” he said.

The state disputed the characterization and said that the number of opportunity districts was proportional to the percentage of the state’s population that is Hispanic.

“There is little resemblance to the Texas of (50) years ago,” said Schneck, the state’s lead lawyer. He said “those days are over,” referencing the state’s past Jim Crow laws, and that there are two viable political parties in Texas is evidence of that change.

The judges have said they expect the trial to last through the end of next week.